Pectus excavatum

Does anyone have any experience with pectus excavatum? I noticed my 6 week old son has a little dent in his chest, more noticeable when he breathes in and cries. I’m not sure if it is pectus excavatum but I saw similar pictures of babies online. I have a zoom appointment today and the dr said if it is it’s a very mild case but we won’t know how big it’ll get until he gains more, or it could just be normal because his bones aren’t fully hardened. Any opinions?

This is my son, not a great picture of the indent.